Dust separating apparatus



Aug. 4, 192. "AQJQSAC E-TT 2,050,231

I DUST SEPARATING APPARATUS Filed July 22, 1931 Patented Aug. 4, 1936UNITED STATES PATENT OFFICE DUST SEPARATING APPARATUS Application July22, 1931, Serial No. 552,351

3 Claims.

The invention relates to an air washing or dust separating apparatuswhich may be used in the manufacture of fertilizer in separating thefine dust from the coarser comminuted material or in cleaning sand inthe manufacture of bricks or for cleaning various granular materials.

While there is a considerable variety of such apparatus on the market,it is all relatively elaborate and expensive and not proportionatelyeificient. The present invention has as its object the production of asimple and efficient apparatus for this purpose which can be produced inquantity at a comparatively small cost.

In accordance with the theory of operation of the improved apparatus,the material to be separated is introduced at the top center and passeddownwardly over a spreader. The air used in washing or separating isdirected downwardly in contact with the material as it strikes thespreader and through the stream of material as it drops from thespreader. After the first separation the washing air is deflectedupwardly and passed again through the stream of solid and dust, thistime in the opposite direction after which it enters an area in whichthe air velocity is checked, the dust which is carried upwardly by thereverse current being permitted to settle in the machine when it is leddownwardly and discharged, the solid on the other hand passes directlydown from the spreader without being in any way deflected by the airdraft being discharged by way of a chute at one side of the dustdischarge or in any convenient manner.

In the accompanying drawing I have illustrated an air washing apparatusembodying the features of the invention in the preferred form.

In the drawing:

The figure is an elevation of the apparatus, a portion being broken awayto show the internal construction.

Referring to the drawing by numerals, the construction shown consists ofan outer cylindrical casing I, to the bottom of which is secured a lowersection 2 shown as of conical form and referred to herein as an inclineddischarge memher 2. This, in eifect, forms the lower half of the casingthe inclined discharge member being secured to the casing by means offlanges 3. Within the casing near the top is a fan 5 having its bladeshorizontally disposed and its axis vertical. This fan as shown ismounted on a hollow vertical shaft 5 carried in suitable bearings 6 atthe top. To this shaft is secured a bevel gear I driven by a bevelpinion 8 mounted on a horizontal shaft 9 carrying a pulley II! at theside of the casing. The hollow shaft 5 is suitably connected at itsupper end to a funnel II. Surrounding the fan 4 extending downwardly andshown as tapering downwardly therefrom is a frustro-conical member I2.This is open at the 5 top and bottom, and with this as with the otherconical members while the frusto-conical formation is considereddesirable it is not regarded as essential to the operation, taperedmembers of other than circular cross section being regarded 10 asoperative with almost equal efficiency, the word conica being usedthroughout for convenience and not for the purpose of limiting themeaning of the description or claims to members of circular crosssection. The nozzle member may be 15 supported by strips or straps I3extending outwardly to the casing.

Near the center of this nozzle member is a deflector or spreader I4 forthe material to be separated. This spreader is shown as in the form 20of a cone having the apex turned upwardly toward the center of the fan.The spreader may be supported in any suitable manner, as by means ofsheet metal strips I6 secured to the spreader and to the inside of the.nozzle extending outwardly radially from the spreader. As shown, thespreader I I is of a diameter at the base slightly less than thediameter of the opening at the bottom of the frusto-conical member I2,said opening being indicated by reference character I5.

Surrounding the discharge opening of the member I2, at I5 and spacedoutwardly therefrom and extending well above said discharge opening isan air deflector funnel I6 supported in the lower half of the casing 2in any suitable manner as by means of sheet metal strips II. All fourconical members, nozzle I2, spreader I4, air deflector funnel I6 andinclined discharge member 2 are preferably arranged in axial alignmentas shown, but this arrangement as well as the exact shape, may be variedto a considerable extent without departure from the principle of theinvention. The air deflector funnel I6 is formed at the bottom with adischarge chute I8 for the solid material extending out through thecasing and the lower inclined portion 2 of the casing is provided with abottom discharge opening I9 for the dust.

' In the operation of the apparatus the commi- 5 nuted material to beseparated which may be sand or coal, fertilizer or any material whichcan be treated in this way, is introduced at the funnel II and passeddownwardly through the hollow shaft 5, the fan 4 being operated in righthanded rotation as seen from above by means of the pulley ID. Thematerial passed downwardly through the tubular shaft 5 and dischargedtherefrom comes first in contact with the spreader l4 forming thematerial into a cylindrical stream which tends to pass downwardlythrough the opening I5 at the bottom of the frustro-conical member I2,which surrounds and leads the air downwardly from the fan. The draftthus di-- rected downwardly through member I2, being confined betweenthe member I2 and the deflector I4 passes with considerable velocity andin a downwardly inclined direction through the cylindrical stream ofmaterial being treated which drops from the deflector I4 toward theopening in the nozzle at I5. V

In this way the air draft is caused to take up a considerable proportionof the dust from the material. The solid particles, as distinguishedfrom the dust, fall directly into the air deflector funnel I6 where theyconverge toward the passage I8 which is filled almost completely by thesolid portion of. the material tending to permit the passage of airtherethrough.

The air draft, as it passes downwardly from the nozzle opening I5, comesin contact with the funnel I6, thus closed at the bottom and the mainportion of this air is deflected upwardly through the opening 20 betweenthe member I2 and the air deflector. funnel I6, passing again throughthe stream of material which is now dropping from the edges of theopening I5 in the member I2 and through said opening and into deflectorfunnel I6. Inthis way a second separation and washing is efiected by theair current, and the dust which is thus almost completely removed fromthe material being treated, is carried upwardly with the air current tothe space 2I between the casing I and the frusto-conical member I2. Atthis point the cross sectional area of the availableair passage isgreatly increased as compared to the area at 20, hence the velocity ofthe air is almost completely lost on account of its tendency to expand.In this way the dust is permitted to settle, falling on the walls of theinclined portion 2 of the casing by which in the form of the inventionshown it is led to the dust discharge opening IS. The fan in itsoperation, as already described, gradually draws the air from space 2|upward to the suction side of the fan at I2I from which point theoperation is repeated, the air being thus continuously circulated, thedust being dropped therefrom in the space 2| and discharged at I9. Theclean solid on the other hand is collected by deflector funnel I6 anddischarged simultaneously from the chute I8 so that the solid materialis discharged continuously from the chute I8 and the dust from thedischarge opening I9, throughout the operation of the machine.

I have thus described specifically and in detail a dust separatingapparatus embodying the features of the invention in the preferred formin order that the manner of constructing, applying, operating and usingthe invention may be fully understood, however, the specific termsherein are used descriptively rather than in a limiting sense, the scopeof the invention being defined in the claims.

What I claim as new and desire to secure by Letters Patent is:

1. The combination in a dust separator of a fan, means for driving thefan to provide a downward current of air, a frusto-conical membersurrounding the fan, means for feeding comminuted material downwardlyinto said member at the center, a spreader beneath and in line with saidfeed and in said member so that the downward current of air passesthrough the material which is formed into a curtain by the spreader, anair deflector beneath the said member adapted to catch the solidmaterial and pass it downwardly therefrom and to turn the air upwardlybetween the deflector and the frusto-conical member, a settling spacefor the air immediately above the deflector, the apparatus having aclosed casing to provide for continuous circulation of the air, andbeing provided with a downwardly inclined portion beneath the settlingspace with an opening to discharge the dust, the air deflector having adischarge for the solid material of relatively small cross section ascompared to the free cross section of said member around the spreader,the cleaned material serving to retard the passage of air through thedischarge opening of the deflector causing the main portion of the airto be retained and deflected upwardly into the settling space.

2. In a separating apparatus a closed casing, a fan therein having ahollow shaft extending downward through the casing, means forintroducing the material to be treated through the hollow shaft, afrusto conical member surrounding the fan, the frusto-conical memberhaving an opening at the top with which the fan registers,

and means for driving the fan to force air downwardly into the casing,and a stationary spreader for the material beneath the fan, a deflectorfunnel surrounding the bottom of the said member, a settling spaceadjacent the upper portion of the deflector, a discharge for the dustbeneath the settling space and leading downwardly therefrom, and adischarge passage for the solid material leading downwardly from thedeflector the latter discharge being of relatively small cross sectionas compared to the free cross section of the frusto conical memberaround the spreader, the solid material serving to retard the passage ofair from the deflector and causing the bulk of the air to be deflectedupwardly into the settling space whereby the dust is dropped from theair and passed downwardly to be discharged.

3. In a dust separator, anouter casing having a lower portion ofdownwardly tapered conical formation with a dust discharge opening atthe bottom thereof providing an inclined discharge member, a hollowvertical shaft rotatably mounted in bearings in the top of said casingand projecting into said casing for introducing comminuted materialsintothe casing, means for rotating said shaft, a fan having upwardly andforwardly inclined blades mounted on saidshaft to rotate therewith in ahorizontal plane to effect a downward draft of air in said casing, anopen ended frustro-conical member of downwardly reducing cross sectionhaving its upper end surrounding said fan, providing a slight clearancetherefrom, said upper end beingspaced inwardly from said casing toprovide an annular passage for the air around said frustro-conicalmember, which member extends downwardly from the fan and has a reducedopening below the fan, an upright conical spreader axially aligned withsaid hollow shaft and said fan and contained wholly within saidfrustro-conical member, said spreader being adapted to form the currentof air issuing from said fan into a circular curtain, a downwardlytapered air deflecting funnel in said casing into which funnel the lowerend of the frustro-conical member projects, there being an 75 memberproviding a settling space for the rising air which is deflected by saidfunnel in which space the dust separates from the air and falls on theinclined discharge member to be discharged through said dust dischargeopening.

AUGUSTUS J. SACKE'I'I.

